Saturday, March 3, 2018

adobe illustrator - Uniform Scattering with vector


I'm attempting to create a random spread of dots to create a gradient look. I'm getting really close to the effect I want by blending two scatter brushes. The issue I'm having is that the blended brushes creates unwanted lines, and the dots run into each other. I keep adjusting the settings with no luck.


Here's the effect I'm wanting to achieved.



  • Smooth transition

  • On Circular path


  • Dots don't converge

  • Scattered at random-ish


Gradual Scattered effect


Here's how close I'm able to get:



  • Blended scatters create unwanted lines

  • Dots converge

  • Spacing isn't gradual from edge to center



What I'm able to achieve



Answer



Astute Graphics has an Illustrator extension "Stipplism" . It obviously can convert greyshades to dot densities + more. I haven't it, but check it here https://astutegraphics.com/software/stipplism/


A radial gradient can be the first objects to get it.


If you do not want Stipplism and the blending approach isn't good, then you can trace a bitmap, which has the effect.


The bitmap is easily copyable from GIMP. There you make a radial gradient and dither it to 1 bit indexed mode.


At first make an empty image, have quite low pixel dimensions to keep Illustrator load reasonable. Here is a 200 x 200 pixels RGB image and a radial gradient is just under construction:


enter image description here


There's a circular selection to keep the edges empty. The gradient isn't fully linear. There's a middle stop to make the sparse center wider. The shade range is only about 60%...100% white, because darker greys will make contiguous blocks in the dithering process.


Image mode is converted from RGB to Indexed (it's in the Image menu). Here's the dialog



enter image description here


I converted it back to RGB, but it seems to work in Illustrator as well when it's copied and pasted as is. Here's the tracing dialog:


enter image description here


Note: the accuracy is stretched to maximum in the tracing settings and white is ignored.


The result contains nearly square dots. If you want round ones, do the following:



  • expand the live trace to make the result editable

  • with Path > Simplify transform all curves to straight lines

  • apply filter Stylize > Round corners; you must measure one dot in high zoom to see the proper radius if you want to be careful. Fortunately too big radius doesn't harm.

  • make the result editable with Object > Expand Appearance



Here's a zoomed picture of the final result:


enter image description here


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